Intraductal papillary mucinous neoplasm-derived pancreatic cancer of the ventral duct in patient with pancreas divisum: a case report.

Pancreas divisum, a congenital failure of fusion between the dorsal and ventral pancreatic buds, occurs in ~10% of the population. The prevalence of intraductal papillary mucinous neoplasm (IPMN) of the ventral duct in pancreas divisum is not well established. Malignant transformation is exceptionally rare, with this case being the first documented in the USA. A 74-year-old man presented with new-onset obstructive jaundice. A computed tomography of the abdomen and pelvis showed pancreas divisum with a 4-cm cystic mass causing a 1.8 cm ventral pancreatic duct dilatation, concerning for an IPMN. Cyst fluid analysis demonstrated elevated fluid amylase and carcinoembryonic antigen. Due to high-risk stigmata, the patient underwent a Whipple procedure and was found to have a 3.5-cm pancreatic cancer arising from an IPMN of the ventral duct. Given the risk of progression, patients with pancreas divisum who develop ventral duct IPMN require careful surveillance and timely escalation of care when appropriate.